A feasibility study of embedded conductive layer fabricated by ion implantation

In order to make polypropylene (PP) have good conductivity and insulation, as well as certain mechanical properties, silver ions were implanted into the surface of PP to explore the feasibility of forming an embedded conductive layer in this work. The experimental results show that the surface resistivity of PP reaches 0.879 MΩ/sq, dropping by 11 orders of magnitude after ion implantation, which indicates that the surface conductivity has been improved. The surface of implanted PP presents a wrinkled morphology and gaps under the scanning electron microscope (SEM), indicating that ion implantation can cause local high temperature and thereby lead to melting on the surface of the sample. For this reason, silver ions can be easily embedded below the sample surface. The energy dispersive spectrometer (EDS) characterization result shows that the penetration depth of silver ions can reach about 2.5–7.5 μm. To further improve the surface conductivity of the sample, we coated carbon black on the surface of PP and then carried out ion implantation. Due to the embedding of carbon black particles, the surface resistivity of the sample further decreased by an order of magnitude, and the change with time was more stable. The results of EDS, FTIR and XRD experiments show that both carbon black and silver ions are embedded inside the surface of the samples. In summary, the method of ion implantation after coating carbon black can form an embedded conductive layer with good conductivity and stability on the surface of PP, which realizes the design concept of integrating the conductive layer and the matrix layer into an integrated layer. The embedded conductive polymer film can be prepared in this way, which serves as a new idea for the development and application of insulating materials.